Live data from Hacker News

SpaceX’s Falcon Heavy successfully launches

techcrunch.com

851–860 of 926 posts

Re: SpaceX’s Falcon Heavy successfully launches

#851

Earlier quoted context omitted.

That would be $3200k for each, but they are made out of titanium, not platinum, and most of the cost is in the work, not material. I'd like to know the price too though.

Yep - Titanium is notoriously difficult to work with.

Titanium isn't particularly terrible to machine. Nothing is hard to machine if your budget can cover the correct tools and you machines can provide the right setting to run those tools.

Your typical mechanical engineer fresh out of school has incredibly limited experience when it comes to things that are not stupid-proof to work with (engineering programs have other priorities). They then go on to build specialized knowledge in various subjects and usually more on the design side, not the execution side. Of course someone who designs plastic molds or simulated impeller designs all day is going to create a black box around things that aren't their specialty. You don't care about how the impeller or mold is made other than knowing that it can be made, what its material properties are and knowing that actually making it involves a bunch of details you don't know so you offload it to a 3rd parts (for the same reasons someone else is having you design the impeller or the mold).

A bunch of engineers and otherwise smart people on the internet saying that titanium is like computer programmers saying residential electrical is complicated or web devs complaining about bash. It really doesn't mean much but people who have no experience with this things tend to think the people who only have a shred know what they're talking about.

It's not difficult. Most other people just know they don't know how to do it and that they don't know what they'd need to know to go about learning how.

Re: SpaceX’s Falcon Heavy successfully launches

#852
post #802
post #611

Earlier quoted context omitted.

The latest hardware revision that's expected to be the mainstay for F9 flights going forward. Has better performance and addresses some reusability issues discovered in earlier blocks.

But if they weren't on this flight, how sure is SpaceX that they are more reliable? But yeah, that's just a question from my mind. This launch was amazing, the future in the making right here.

The plain is to lock down block 5's design so it can be man rated which in itself would make it more reliable. This will probably not happen until they fly them a few times though so that wouldn't mean the first block 5s would be more reliable.

Re: SpaceX’s Falcon Heavy successfully launches

#853
post #618
post #489

Earlier quoted context omitted.

It's not quite our generation's "one small step for Man" moment (I'm saving that for when we actually land a human on Mars) but it's damn close.

If you haven't seen it there is some, according to Armstrong 'persuasive', evidence[0] that he did in fact say 'one small step for a man'. [0] https://www.space.com/17307-neil-armstrong-one-small-step-qu...

[deleted]

Re: SpaceX’s Falcon Heavy successfully launches

#854
post #726

Earlier quoted context omitted.

Have you seen an approximate price for those fins anywhere. I saw the interviews, but I want to know how expensive is expensive.

Platinum is USD$32K per KG, so if the platinum grid fins are 100KG, then they would cost > $300K each just for materials. With 4 per booster that might be a million dollar price tag for the grid fins.

KU Leuven states the grid fins at 41kg. (The same volume of material would be 193kg in platinum)

Re: SpaceX’s Falcon Heavy successfully launches

#855
post #795
post #785

Earlier quoted context omitted.

So difficult that the SR-71 leaked fuel before starts and had to be re-fueled right after take-off. https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Fuel

The Blackbirds leaked because they had engineered gaps to allow for heat expansion.

I bet SpaceX could engineer something in spec that wouldn't leak fuel or need to be immediately refueled though.

Re: SpaceX’s Falcon Heavy successfully launches

#856
post #450

Earlier quoted context omitted.

I interviewed at BlueOrigin ~3.5 years ago, my impression was they're very old fashioned and secretive. Not necessarily a bad thing for such critical systems (though I think SpaceX has the better model/culture even if I know it's not for me), but I was applying for a backend role using Spring and hoping to get in on a program they had at the time where you could move around the various departments like avionics and s…

I interviewed for the superlative job title “Spaceflight systems avionics software engineer”. Contrary to your experience, I found the process to be very casual. They told me not to bring my resume, but to put together a PowerPoint presentation about my life. For one of my interviews the interviewing engineer didn’t even show up and his boss came in later and said (paraphrased): “you made it this far so I guess you’r…

They sound like a mess. When an interviewer doesn't even show, that's not a good sign. When this boss says, "I guess you're good enough", that's a worse sign. This is rocket science, after all.

Re: SpaceX’s Falcon Heavy successfully launches

#857
post #785

Earlier quoted context omitted.

So difficult that the SR-71 leaked fuel before starts and had to be re-fueled right after take-off. https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Fuel

That has nothing to do with titanium and everything to do with material expansion, the design/shape of the assembly and ambient vs operating temp.

Cant reply directly to wand3r for some reason. Re his comment spacex could engineer something that wouldn't leak or need instant refuelling - I wouldn't be surprised if they could - but they have around 30 years of advancements to help them!

Re: SpaceX’s Falcon Heavy successfully launches

#858
post #802

Earlier quoted context omitted.

But if they weren't on this flight, how sure is SpaceX that they are more reliable? But yeah, that's just a question from my mind. This launch was amazing, the future in the making right here.

The plain is to lock down block 5's design so it can be man rated which in itself would make it more reliable. This will probably not happen until they fly them a few times though so that wouldn't mean the first block 5s would be more reliable.

I recall reading or hearing yesterday that space-x no longer plans to man-rate any falcon-9s instead reserving that for the BFR.

Re: SpaceX’s Falcon Heavy successfully launches

#859

Earlier quoted context omitted.

Can confirm this was the greatest thing I've ever witnessed in my life. https://youtu.be/AGPH_i0ZlyM?t=56

There's something awesome (in the literal sense) and unsettling about watching something and being able to say "I am witnessing history".

[deleted]

Re: SpaceX’s Falcon Heavy successfully launches

#860
post #793

Earlier quoted context omitted.

I'm kind of glad they had something fail. That means maybe they learned something new to improve the next shot.

The rocket ran out of engine igniter fluid. It had enough to light the centre engine, but not the two side engines. That seems to imply they were trying to do a 3-engine landing, which they tested recently in the 'failed to expend the rocket' incident. This might explain why they miscalculated the igniter requirement since they don't have much experience with 3-engine landings.

Is the normal landing a 1-engine landing? If so, is the advantage of a 3-engine landing that it requires less fuel due to having a much shorter 'suicide burn'?
Post reply on HN